Solids are the best at conducting heat.
Another name for these two words is "constant" and you want to have a "constant", because you want something to compare your experimental group to, to see whether data had changed or not. So you have placebos or a double- blind to compare your experimental group to it and also so you know you don't have a bias or anything in the study.
To solve this task we have to make a proportion, but firstly we have to set up all the main points : so, the distance is s=r(B), that has its <span>r=radius,B=angle in rad
velocity v=ds/dt= w(r)
Do not forget about </span> w = angular speed in rad/s and

Now we can go to proportion




SOLVING FOR A :



or something about <span>10 mph --- SOLVING FOR B.
</span>I'm sure it helps!